Portable air filter



FIG. 1 is a perspective view of a portable air filter illustrating ournew design;

FIG. 2 is a front elevational view thereof, on a reduced scale;

FIG. 3 is a rear elevational view thereof, on a reduced scale;

FIG. 4 is a top plan view thereof, on a reduced scale;

FIG. 5 is a right side elevational view thereof, on a reduced scale;

FIG. 6 is a left side elevational view thereof, on a reduced scale; and

FIG. 7 is a bottom plan view thereof, on a reduced scale;

The ornamental design for a portable air filter, as shown.